And stockton borton



(No Model.)

C. H. WILLCOX & S. BURTON. FEED MECHANISM FOR SEWING MACHINES-N0.1572,041. Patented Nov. 24, 1896.

UNITED STATES PATENT OFFICE.

CHARLES H. IVILLOOX, OF NEIV YORK, AND STOCKTON BORTON, OF

BROOKLYN, NEW YORK, ASSIGNORS TO THE \VILLCOX & GIBBS SEW- ING MACHINECOMPANY, OF NEIV YORK, N. Y.

FEED MECHANISM FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 572,041, dated November24, 1896.

Application filed August 10, 1895.

To all whom it may concern:

Be it known that we, CHARLES H. \VILLCOX, of New York, and STOCKTONBORTON', of Brooklyn, New York, have invented new and usefulImprovementsin Feed Mechanism for Sewing-Machines, which improvementsare fully set forth in the following specification.

This invention has reference to the feedmovement of a sewing-machine,and particularly to a feed mechanism wherein the backand-forth movementof the feed-bar is derived from a feed-eccentric on the main shaft, orit may be any continuously-rotating shaft'of the machine. The object ofthe invention is to provide means for varying or regulating the lengthof stitch.

According to the present invention the length of the horizontalmovements of the feed-bar is regulated by adjusting the position of thefeed-eccentric relatively to the axis of its shaft, and the inventionembraces special means whereby this adjustment is effected. Thesespecial adjusting devices are not necessarily limited to use inconnection with a feed-eccentric, but may obviously be employed inconnection with any eccentric or crank whose throw it"is desired tovary. The eccentric is carried by a suitable support, preferably a disk,which is connected by screws with a disk or pulley fast on the shaft, sothat the eccentric turns with the latter. These screws, however, passthrough radial slots in the eccentricsupport, so that the latter can beadjusted radially of the shaft, the eccentric being held from slippingby the pressure of suitable friction washers surrounding the shanks ofthe connecting-screws or by other equivalent means. The adjustment iseffected by a cam-disk interposed between the fast disk and theeccentric-support and mounted loosely on the hub of the former. Thecam-disk is provided with concentric slots, through which theconnecting-screws pass freely, and with a cam-groove, into which entersa crank-pin on the eccentric-support. By turning the cam relatively tothe main shaft and the eccentric the action of the cam surface or sloton the crank-pin moves the eccentric transversely to the axis of theshaft,

varying the throw of the eccentric. Instead Serial No. 558,850. (Nomodel.)

of turning the cam the same effect is obtained by turning the main shaftand holding the cam stationary, and this is the preferred mode ofoperation. For this purpose the cam has a peripheral notch, and amovable push-pin is provided having a tooth to enter said notch, so thatby depressing the pin and engaging its tooth in the notch the cam isheld stationary, overcoming the friction of the washers, while the mainshaft is turned the desired distance to vary the throw of the eccentric.In order that the adjustment may be eifected with ac curacy, a series ofgraduated marks are arranged on the periphery of a disk carried by theshaft, (which may conveniently be the fast disk .already referred L0,)which marks show through an opening in the frame of the machine. Thegraduated marks are preferably figures indicating each a certain numberof stitches to the inch, and the notch in the cam-plate is so arrangedrelatively to the markings on the disk that when the former is arrestedby its stop the figures exposed through the opening will indicate thelength of stitch to which the machine is at that time adjusted. Then tovary the adjustment the operator has only to turn the shaft forward orbackward until the number corresponding to the desired length of stitchappears through the opening.

In the accompanying drawings, which form part of this specification,Figure 1 is an elevation of part of a feed-actuating mechanismcontaining the present invention, the casing or frame of the machinebeing partly broken away. Fig. 2 is a vertical section-on the axis ofthe shaft through the variable eccentric and its adjusting mechanism.Fig. 3 is an elevation of the right-hand side of the eccentrio-support;and Fig. at is a face view of the adjusting-cam, showing also itsstop-pin.

Inasmuch as this invention relates solely to the means for adjusting aneccentric forming part of the mechanism for driving a feed-bar, andinasmuch as the construction of the connecting devices between theeccentric and feed-bar forms no part of the invention, such devices arenot shown in the drawings. The connecting devices may be of the generalform shown in United States Letters Patent No. 413,699, dated October29, 1889, orof the improved form shown and described in. application ofCharles II. \Villcox filed August 10, 1895, Serial No. 558,851.

A represents the main shaft (or it may be any suitable shaft) of asewing-machine journaled in bearings of the hollow arm B, carried bythe-vertical standard 13 and carrying the feed-eccentrics E E. Theformer is designed to impart to a feed-bar its horizontal motionsthrough a pi'tman Q and other suitable connecting mechanism, while thelatter imparts the risingand-falling movements through a pitman Q. Theeccentric E is the adjustable eccentric, the length of stitch beingobviously proportional to its throw. As shown, it is formed in one piecewith the disk E herein termed the eccentric-support, and has ashaft-hole enough larger than the shaft A to permit the desired range oflateral displacement. Adjacent to support E is an-, other disk I, hereintermed'the adj ustingcam, which is supported loosely upon the hub of awheel G, which is fast on the main shaft. As shown, wheel G is in onepiece with a driving-pulley II, but that is merely a matter ofconvenience.

Eccentric E is attached to fast wheel G, and consequently to the mainshaft, by means of screw-pins e, passing through the support E and cam Fand tapped into wheel G. These screw pins, however, pass through radialslots e in support E so that the latter can move for a limited distanceradially of the shaft, and through concentric slots f in the cam F, sothat the latter can turn relatively to the shaft through an are limitedby the length of the slots. To hold these adjustable parts fromslipping, spring friction-washers e are placed under the heads ofscrew-pins 6. Support E has on the face adjacent to the cam F acrank-pin h, carrying an antifriction-roller h, which engages in aneccentric or cam groove f in cam F.

Such being the construction and relative disposition of the parts it isobvious that when the cam F is turned axially with reference to theshaft the edges of cam-groove f, acting on pin 72, shifts the positionof support E and eccentric E transversely across the shaft A, increasingor diminishing the throw of the eccentric according to the direction inwhich the cam is turned. In order to turn the cam relatively to theshaft, sufficient force must be exerted to overcome the resistance offriction-washers 6 For the purpose of making the adjustment the cam isprovided with a peripheral notch 7e, and adjacent to the periphery ofthe cam is a stop-pin supported on the end of a fiat .spring 70 in ahole in the casing and having a knob on the outside of the latter and adog or tooth on its inner end. Pin 7c is normally held out of engagementwith the notch 70 by means of the spring 20 To change the adjustment ofthe feed-eccentric, the oporator presses in the stop-pin k and turnsshaft A by means of hand-wheel A until the point of the pin snaps intothe notch 70. He keeps his finger firmly pressed on the pin 70, thusholding the cam stationary,while he turns the shaft forward or backward,according as it is desired to increase or diminish the throw of theeccentric. In this movement crankpin 7L traverses the cam-slot f,effecting the desired adjustment.

In order that the adjustment may be effected accurately, it is necessaryto provide a scale or indicator of some sort. To this end the rim ofwheel G is provided with a series of graduated marks each of which ismarked with a number indicatin g in this case so many stitches to theinch. These marks are so placed with reference to the stop-pin 7t" andnotch 70 and with respect to an aperture g or window in the casingopposite wheel G that when the cam is engaged by the stop-pin the numberthen appearing through the aperture indicates the number of stitches tothe inch the machine is making. The operator can thus ascertain readilythe length of stitch to which the machine is adjusted, and to change toa longer or shorter stitch turns the shaft (while holding the camstationary) until the desired number appears through aperture g.

In the construction shown the cam has two notches 70 at opposite sidesof its periphery, and the scale of figures representing differentlengths of stitch is duplicated onopposite sides of wheel G, so that inany case it will only be necessary to turnthe main shaft through adistance less than half a revolution before the stop-pin engages one ofthe notches.

Obviously the details of construction herein shown and described may bemodified within wide limits without departing from the spirit of theinvention.

Having now particularly described our invention, what we claim as new,and desire to secure by Letters Patent, is-

1. In a feed mechanism for sewing-machines, the combination with arotating shaft, of an eccentric connected with said shaft so as torotate therewith, but adjustable radially thereof, an adjusting-cammounted loosely on said shaft, frictional clamping devices for holdingsaid cam and eccentric in theiradjusted positions, and a connectionbetween the cam and eccentric whereby the rotation of the cam relativelyto the eccentric shifts the latters position radially of the shaft,substantially as described.

2. In a sewing-machine, the combination with a rotating shaft, of aneccentric connected therewith for rotation but adjustable radiallythereon, an adjusting-cam rotatable on said shaft, a connection betweenthe cam and eccentric whereby the rotation of the cam relatively to theeccentric shifts the latter radially of the shaft, and a graduated scalefor indicating the extent of movement of the cam relatively to theeccentric, substantially as described.

3. In a sewing-machine the combination with a rotating shaft, of aneccentric adjustable radially thereof, an adj usting-caln rotatable onsaid shaft, frictional clamping devices for holding said eccentric andcam in their adjusted positions, and a stop-pin or catch for engagingand holding said 7 cam against the friction of said clamping devices sothat the shaft and eccentric can be turned, and the position of thelatter shifted radially while the cam is held stationary, substantiallyas described.

4. In a sewing-machine the combinationv ronnected with said eccentricand adjustable axially on said shaft but normally rotating therewith, adisk fast on said shaft carrying a graduated scale for indicating therelative positions of the shaft and eccentric, and a catch or stop-pinfor holding the cam stationary while turning the shaft to change theadjustment of the eccentric, substantially as described.

6. The combination of the rotating shaft, the eccentric and its supportadjustable radially thereof, a cam mounted on and adjustable axially ofsaid shaft, and having a camgroove, a crank-pin on saideccentric-support entering said groove, a disk fast on the shaft,

screws passing through radial slots in the ec-' centric-support andconcentric slots in the cam and entering threaded holes in said disk,and friction-washers surrounding the shanks of said screws,substantially as described.

In testimony whereof we have signed this specification in the presenceof two subscribing witnesses. I

CHAS. H. WILLCOX. STOCKTON BORTON.

\Vitnesses:

J. PABMLY, J. H. OooKE.

